The clutch

Pressure plate and friction disk fabricated by ClutchNet
Cost - $275
Aluminum flywheel fabricated by Fidanza
Cost - $350

Flywheel assembly The clutch assembly was the final step before putting together all the drive train components. I must say that on the images below is shown my second attempt. First one (stock clutch and pressure plate) was slipping at near maximum torque, so I had to upgrade it. Evaluate your clutch while transmission is still apart. Changing it later is a major hassle.

Some people prefer to ditch the clutch all together and couple the motor and transmission input shafts directly. This is debatable issue having its pros and cons, and the possibility of doing that greatly depends on the particular car model as well as expected usage of different gears. Some transmissions are pretty forgiving for shifting without depressing the clutch - you can practice and quickly learn to equalize the motor speed with current tranny shaft speed close enough to be able to shift.

Well, Honda CRX is unusual car in many respects, including this. Besides the opposite from other cars motor shaft rotation direction (CW for forward move), it is very difficult to upshift and practically impossible to downshift without disengaging the clutch. To make long story short - to go without clutch was the option I had to avoid, although second gear alone covers my usual driving needs.

The flywheel in an EV serves only as a means to attach the pressure plate to, there is no need for it to be massive. With my motor set to run at up to 8500 RPM, the extra mass becomes really dangerous: if the flywheel fractures at that speed, major damage and probably serious injury is unavoidable. For that reason I ordered aluminum flywheel, this particular is made by Fidanza corp. Of course it had to be modified a bit (starter ring gear removed) and balanced together with the pressure plate. To assure firm grip, the pressure plate was also replaced for one with double springs. Friction disk is replaced for 3 puck racing one, made by Clutchnet corp. Components are shown below:

Flywheel The front (friction disk side) of the flywheel as comes from manufacturer. Friction material is bolted with screws and ...
Flywheel ... secured with nuts on the other side.
Flywheel Front side of the pressure plate.
Flywheel Note double spring. Perhaps overkill, but guarantees that the clutch won't slip (as it did with stock components).
Flywheel Back side of the pressure plate.
Flywheel Sintered 3 puck racing friction disk
Flywheel Alignment tool - centers friction disk on the flywheel surface.
Flywheel Couldn't wait - removing starter ring gear. One cut with angle grinder does it easily

Drive train assemblyAfter the flywheel with the pressure plate was dynamically balanced, the assembly begins. The steps are as follows:

- Shaft coupler is mounted on the motor shaft.
- Adapter plate is placed onto the motor flange and the bolts are hand tightened;
- The flywheel is bolted to the shaft coupler. I've used Lock Tite on the bolt treads.
- The friction disk is placed to the center of the flywheel and sandwiched with the pressure plate. Alignment tool inserted into the friction disk and pilot bearing keeps the disk centered.
- The plate centering dowel pins are inserted in respective holes on the transmission
- Either the motor or transmission is hanged from the hoist so its shaft is facing down; the transmission (or the motor) then is put on the floor shaft straight up.
- The motor with mounted clutch is lowered onto the transmission clutch assembly such that it's splined shaft goes into the splines in the friction disk. Of course, alignment tool is removed. Slight rotation of the flywheel through the starter hole will help the splines to slide in.
- Once the splines are meshed, the dowel pins go into the adapter plate and the holes for the plate mounting bolts are lined up.
- The mounting bolts holding adapter plate to the transmission are inserted and tightened
- The bolts attaching the motor to the plate are tightened as well. Done.

Assembly The plate centered on the motor flange.
Assembly The motor on the floor with the shaft facing straight up for easy flywheel mounting.
Assembly Flywheel is bolted to the shaft coupler
Assembly The friction disk placed on the flywheel.
Assembly Side view of this step Alignment tool inserted.
Assembly Pressure plate is tightened to the flywheel.
Assembly Close up of this step. Note blue paint marks the position of the pressure plate as it was balanced.
Assembly Lowering the motor onto transmission. Actually on my second attempt transmission was on the top and lowered. Doesn't matter.
Assembly Close up of this critical step. Dowel pins sticking from the bell line up with respective holes in the plate.
Assembly Pressure plate is visible through the starter hole. Rotating by hand helps splines to mesh.
Assembly Don't forget to put bolts like this one in place ahead of time, or else you'll repeat all exercise again...
Assembly When the splined shaft slides in completely, after inserting mounting bolts I flipped whole drive train to tighten all the bolts.

Transmission and motor bolted togetherAfter all dowel pins are in hand tight all the bolts attaching plate to the clutch bell and motor to the plate. Rotate the flywheel through the starter hole - nothing should rub or otherwise interfere smooth movement. If so, tighten all the bolts and nuts around in 2 steps. I'd suggest using Lock Tite on the threads. One drop on each bolt is enough, some of such compounds are so strong that you can damage thread should you disassemble the unit later.

Assembly The bolts holding plate to the transmission and the motor to the plate.
Assembly When both flanges overlap, it's difficult to tighten anything. I had to make the notch in the motor flange.
Assembly Side view of assembled drive train.
Assembly Other view of the drive train. Former rubberized engine support is installed back.
Assembly The sockets for the drive half shafts have to be plugged. You don't want anything fall into the gear box!
Assembly Close up of the support brackets mounts.

Clutch lever Later on a small detail came up: the clutch actuation cord goes from the lever straight up in the stock tranny. In my case the inverter case is sitting just 10 mm from the top of the adapter plate, so the clutch cable runs right into it. The cable cannot be bent much, so I needed to come up with solution. Well, I redirected the cord to come out at 45 degrees so the inverter no longer interferes. To do that, the lever had to be extended and new loop holding the end of the cord bolted to the existing lever. Also a new bracket where the base of the jacket sits had to be welded up and bolted to the transmission. As long as the pull direction is perpendicular to the new lever position, it works just fine. The photos below illustrate the steps. Warning: the forces on the clutch cable are rather high, so the bracket must be made from the 3-4 mm steel plate, or it will bent.

plate The stock clutch actuator lever and the cord sticking right up
plate The stock lever is cut off and the movement is marked on the metal plate temporary bolted to the lever.
plate The cut portion of the stock lever is welded to a 5mm thick metal plate...
plate ...which is shaped to form "extension" of the stock lever at the correct new angle (about 45')
plate The new thin metal template bracket (left) and real part (right) were made as well.
plate The end result - the cord is at 45' now and does not interfere with the inverter case above. Works just like original.